Method and apparatus for controlling volume

ABSTRACT

Some embodiments of the invention provide a method for controlling the volume of an audio track. This method represents the volume of an audio track with a graph. This graph is defined along two axes, with one axis representing time and the other representing the volume level. A user can adjust the graph at different instances in time in order to change the volume level in the audio track at these instances. Different embodiments use different types of graphs to represent volume. For instance, some embodiments use a deformable line bar.

CLAIM OF BENEFIT TO RELATED APPLICATION

This application is a continuation application of U.S. Nonprovisionalpatent application Ser. No. 10/337,925, now issued as U.S. Pat. No.7,319,764, filed Jan. 6, 2003, entitled “Method and Apparatus forControlling Volume.” U.S. Nonprovisional patent application Ser. No.10/337,925, now issued as U.S. Pat No. 7,319,764 is incorporated hereinby reference.

FIELD OF THE INVENTION

The invention is directed towards method and apparatus for controllingvolume.

BACKGROUND OF THE INVENTION

Controlling volume is often an important aspect of creating multimediacontent. This is especially the case when several tracks of audio aremixed to create the content. Controlling the volume of several audiotracks, however, often requires expensive equipment. Less expensiveequipment often does not provide sufficient control over the volumelevel. In addition, the prior art does not provide a visual andintuitive technique for controlling volume. Therefore, there is a needfor a simple method that controls the volume of an audio track in avisual and intuitive manner.

SUMMARY OF THE INVENTION

Some embodiments of the invention provide a method for controlling thevolume of an audio track. This method represents the volume of an audiotrack with a graph. This graph is defined along two axes, with one axisrepresenting time and the other representing the volume level. A usercan adjust the graph at different instances in time in order to changethe volume level in the audio track at these instances. Differentembodiments use different types of graphs to represent volume. Forinstance, some embodiments use a deformable line bar.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth in the appendedclaims. However, for purpose of explanation, several embodiments of theinvention are set forth in the following figures.

FIG. 1 illustrates a deformable line bar of some embodiments of theinvention.

FIG. 2 illustrates a deformation of the volume-control bar of FIG. 1.

FIGS. 3 and 4 illustrate a click-and-drag operation that results in thedeformation illustrated in FIG. 2.

FIG. 5 illustrates an example where the user drags a duration-controlknob associated with a deformity in the volume-control bar.

FIG. 6 illustrates an example of moving a deformity in thevolume-control bar left or right along the timeline by dragging avolume-control knob associated with this deformity.

FIG. 7 illustrates an example of moving the volume-control bar up ordown along a volume-level axis in order to change the volume-levelspecified by a deformity in the volume-control bar.

FIG. 8 illustrates the attributes of a volume marker in someembodiments.

FIG. 9A illustrates a process that creates a volume marker.

FIG. 9B illustrates an example of performing a click-and-drag operationon a portion of a previously defined deformity along the volume-controlbar.

FIG. 10 illustrates an example of drawing a dashed line to assist in thevertical movement of a volume-control knob.

FIG. 11 illustrates a process for modifying a volume marker byperforming a click-and-drag operation on the marker's volume-controlknob.

FIG. 12 illustrates a process for modifying a volume marker byperforming a click-and-drag operation on the marker's duration-controlknob.

FIGS. 13, 14, and 15 illustrate how some embodiments use the volumemarkers specified along a volume bar to define the volume level of anaudio track.

FIG. 16 illustrates an example where the invention is useful in mixingtwo audio tracks.

FIG. 17 illustrates a computer system with which one embodiment of theinvention is implemented.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, numerous details are set forth for purposeof explanation. However, one of ordinary skill in the art will realizethat the invention may be practiced without the use of these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order not to obscure the description of theinvention with unnecessary detail.

Some embodiments of the invention provide a method for controlling thevolume of an audio track. The audio track can be a standalone track, orit can be associated with, or a part of, a visual presentation (such asa slide show, a movie, an animation, etc.). This method represents thevolume of an audio track with a graph. This graph is defined along twoaxes, with one axis representing time and the other representing thevolume level. A user can adjust the graph at different instances in timein order to change the volume level in the audio track at theseinstances.

Different embodiments use different types of graphs to represent volume.For instance, the embodiments described below use a deformable line bar.Specifically, FIG. 1 illustrates a deformable line bar 105 that issuperimposed on a rectangular box 110. This box is a graphicalrepresentation of the audio track. In some embodiments, the line bar 105and the rectangular box are part of a graphical user interface (“GUI”)with which the user can interact through traditional GUI operations,such as click operations (e.g., to select an item), click-and-dragoperations (e.g., to move an item), etc.

Above the rectangular box are a timeline 115 and a time marker 120. Whenthe audio track is playing, the time marker 120 moves along the timeline115 to specify the portion of the track that is playing at each instancein time. A user can also drag the time marker 120 to a particular timeon the timeline 115 to listen to the audio track starting at that time.

In FIG. 1, the volume-control bar 105 is defined by reference to twoaxes. One axis is the above-described horizontal timeline 115, while theother is a vertical volume axis 117. Different embodiments expressdifferent volume indicia along the volume axis. For instance, in someembodiments, this volume axis expresses the volume levels in terms ofpercentages that are to be multiplied with a base volume value. Thevolume-axis value of the volume-control bar 105 at any instance in time(i.e., at any point along the time axis) represents the volume level ofthe audio track at that instance. Initially, this bar is flat about amidrange volume value M. In other words, the initial volume along theentire track is equal to the midrange volume value M.

Through the volume-control bar 105, the user can easily change thevolume level. For instance, this bar has a volume-control knob 125 atits beginning. The user can drag this knob vertically up or down toincrease or reduce the volume level of the audio track. This isillustrated in FIG. 1. In some embodiments, this knob is not visible oris only visible once the user clicks on the start of the bar.

The user can also change the volume level at any point in time bydeforming the bar at that point in time. For instance, FIG. 2illustrates the deformation of the volume-control bar 105 starting at atime t1. As a result of this deformation, the volume-control bar 105 hasthree different portions. These are (1) a flat portion 205 representingthe audio track's volume before the time t1, (2) a ramping portion 210representing the track's volume between times t1 and t2, and (3) a flatportion 215 representing the track's volume after time t2. The flatportion 205 signifies that the audio track's volume before the time t1is constant and equal to the midrange value M. The ramping portion 210signifies that the track's volume changes from the midrange value M toan adjusted value A between the time t1 and a time t2. The flat portion215 signifies that the audio track's volume after the time t2 isconstant and equal to the adjusted value A. Two control knobs 220 and225 specify the beginning and end of the ramping portion 210. Thesecontrol knobs are further described below. Also, some embodimentsspecify the ramp as a smooth spline curve, instead of specifying it as astraight line.

The user can deform the bar through a simple click-and-drag operation.Specifically, to modify the bar, the user can (1) move the cursor to aportion of the bar that is not within a specified distance of a controlknob, (2) perform a click-and-hold operation (e.g., press a mouse buttondown and hold it in a depressed state), (3) drag the cursor to a newlocation within the box 110, and (4) terminate the click operation(e.g., release the mouse button).

FIGS. 3 and 4 illustrate the click-and-drag operation that results inthe modification illustrated in FIG. 2. FIG. 3 shows that a cursor 305is initially positioned at a location 310 on the bar 105. As shown inFIG. 3, the moment that the user starts to perform the click-and-dragoperation at location 310, the two control knobs 225 and 220 are definedon the volume bar. The knob 225 is initially defined at the location ofthe click, while the knob 220 is a time interval (e.g., 0.5 seconds)behind the other knob. These knobs are further described below.

FIG. 4 shows the cursor 305 after it has been dragged to a new position315. As shown in this figure, this dragging specifies a ramp 320 thatdivides a previously undivided portion of the bar (which in this case isthe entire bar) into two portions 325 and 330 that are at differentvolume levels. Once the user drags the cursor to the position 335, theuser terminates the click-and-drag operation (e.g., releases the mousebutton). At this point, the modification illustrated in FIG. 2 isspecified. Some embodiments automatically set the duration of a ramp toa particular value (e.g., 0.5 seconds) in most instances when a portionof the volume bar is deformed and a ramp is defined. This duration,however, can be modified, as further described below.

As shown in FIG. 2, the click-and-drag operation creates two knobs 220and 225 that respectively specify the beginning and end of ramp 210(i.e., specify the beginning and end of the deformation). The knob 220is square and specifies the beginning of the ramp, while the knob 225 isround and specifies the end of the ramp. In the embodiments describedbelow, the square knob is always to the left of the round knob. As shownin FIG. 3, the round knob coincides with the location of the cursorduring the click-and-drag operation, while the square knob typicallyremains a particular time interval behind the round knob.

During the entire click-and-drag operation, the volume level of thesquare knob remains the initial volume level of the bar at the positionthat the user clicked when he initiated the click-and-drag operation. Inother words, the volume-axis value of the square knob 220 is the volumelevel of the audio track before it was changed. On the other hand, thevolume-axis value of the round knob 225 specifies a new volume level forthe audio track. The audio track will be at this new volume level unlessthe bar is modified again.

The knobs 220 and 225 are selectable data points that can be used tomodify attributes of the ramp 210. All control knobs (such as knobs 125,220, and 225) of the volume bar can be dragged through click-and-dragoperations. Specifically, to drag any control knob, the user can placethe cursor over the knob, perform a click-and-hold operation to selectthe knob, drag the knob to the desired location, and then terminate theclick operation.

A user can increase or decrease the duration of the ramp by dragging thesquare knob 220 away or towards the round knob 225. Accordingly, thesquare knob will be referred to below as the duration-control knob. FIG.5 illustrates an example of the operation of the square knob. In thisexample, the user drags the knob 220 in a direction away from the knob225 to increase the duration of the ramp 210. A duration-control knobcan also be moved towards the round knob, in order to reduce theduration of the ramp. The duration-control knob, however, cannot passthe round knob.

The round knob 225 can be used to change the ramp's location or tochange the new-volume level specified by the ramp. Accordingly, theround knob is referred to below as the volume-control knob. FIG. 6illustrates an example of the operation of the volume-control knob. Thisfigure illustrates that the ramp 210 can be moved left or right alongthe timeline by dragging the round knob 225 horizontally right or leftalong the timeline. FIG. 7 illustrates that dragging the round knob 225vertically up or down changes the volume-level specified by the ramp.

In the embodiments described below, the duration-control knob of oneramp cannot move the volume-control knob of another ramp. However, thevolume-control knob of one ramp can move the duration-control knob ofanother ramp. In fact, one ramp's volume-control knob can push anotherramp's duration-control knob so much that the two ramp's volume-controlknobs overlap. When two volume-control knobs overlap, the ramp thatpossesses the duration-control knob that is being pushed (i.e., the rampthat does not contain the volume-control knob that is doing the pushing)is deleted. A user can also delete a ramp by selecting it and pressingthe delete key.

Some embodiments use one or more volume markers to specify the volumelevels along the volume-control bar. These embodiments define an initialvolume marker that specifies the volume level at the start of thevolume-control bar. For each modification along the volume-control bar,these embodiments also define a volume marker to represent the change inthe volume level due to the modification. For instance, in FIG. 2, twovolume markers are defined, an initial volume marker for the initialvolume-control knob 125, and another volume marker for the modification235 specified by the duration-control knob 220, ramp 210, andvolume-control knob 225. Each volume marker is associated with avolume-control knob.

FIG. 8 illustrates the attributes of a volume marker in someembodiments. These attributes include a time value, a volume value, anda ramp duration. The time value and the volume value are respectivelythe time-axis value and the volume-axis value of the volume-control knobthat is associated with the volume marker. For example, in the exampleillustrated in FIG. 2, the time-axis value t2 and the volume-axis valueA are the time- and volume-values associated with the volume-controlknob 225 for this modification. Hence, the time and volume values t2 andA are stored for the volume marker of the modification 235. Similarly,in this example, the time-axis value 0 and the volume-axis value M ofthe knob 125 are the time and volume values of the volume-control knob125 that is associated with the bar's initial volume marker.

The initial volume marker, which is specified at the start of thevolume-control bar, does not have an associated ramp, since it is notdefined for a volume-bar modification. Hence, its ramp duration is null.On the other hand, each volume marker that is specified for a volume-barmodification has an associated ramp, and the duration of this ramp isstored as an attribute of the volume marker. This duration is thedifference between the time-axis values of the duration-control andvolume control knobs of the volume bar modification. For instance, theramp duration of a volume marker specified for the modification 235 inFIG. 2 is the difference in the time-axis values (i.e., (t2-t1)) of theknobs 225 and 220.

FIG. 9A illustrates a process 900 that creates a volume marker. Thisprocess starts (at 905) when it detects that a user has started aclick-and-drag operation on a portion of the volume-control bar that isnot within a specified distance of a control knob. The process thencreates (at 910) a volume marker for the modification to the volume barthat the user has started to make.

If the click-and-drag operation is performed on a portion of apreviously defined ramp, the process also modifies (at 910) the durationattribute of the volume marker of the previously defined ramp. Forinstance, FIG. 9B illustrates one such operation that starts at alocation 970 of a ramp 960 of a previously defined volume modification.A volume-control knob 962 and a duration-control knob 964 define theramp 960. Once the user starts his click-and-drag operation, the ramp960 is modified. Specifically, the location of its duration-control knob964 is given to a duration-control knob 966 of a new ramp 968 that isdefined in response to the click-and-drag operation. For the new ramp968, a volume-control knob 972 is defined to the left of the startlocation 970 of the click-and-drag operation, as shown in FIG. 9B. Theduration-control knob 964 of the ramp 960 moves to the light of thestart location 970. Hence, when the click-and-drag operation isperformed on the previously defined ramp 960, the process modifies theduration attribute of the volume marker of the ramp 960 to reflect themovement of this ramp's duration-control knob 964. In the exampleillustrated in FIG. 9B, if the user starts to drag the cursor to thefight of the location 970, the volume-control knob 972 starts to modifyimmediately the ramp 960. The handling of such a modification will bedescribed further below.

At 910, the process also sets the duration of the volume marker that itcreated at 910. In most situations, the process typically sets thisvalue to 0.5 seconds. The process might set this value to less than 0.5seconds when the volume marker is close to the temporal boundary of theaudio track, or when the volume marker is defined in a middle of apreviously defined ramp that is relatively short.

After 910, the process identifies (at 915) the current y-coordinate ofthe cursor. At 915, the process maps this coordinate to a volume levelCurrent_Vol along the volume axis 117. Next, the process determines (at920) whether the volume level Current_Vol is within a first threshold ofa volume level of any other volume marker of the volume bar 105. If not,the process transitions to 930, which is further described below.Otherwise, to show each volume level that is within the first thresholdof the volume level Current_Vol, the process specifies (at 925) a dashedline for the graphics system to draw. FIG. 10 illustrates an example ofdrawing such a dashed line. In this example, the user is specifyinganother modification 1005 after a first modification 235 on the volumebar 105. The modification 1005 is specified by a volume control knob1010, which follows the cursor's movement. Accordingly, when thecursor's gets close to the volume level prior to the modification 235(i.e., when the volume level of the knob 1010 is within a firstthreshold of the volume level of the initial volume control knob 125),the process 900 specifies a dashed line 1015, which the graphics systemdraws to specify the volume level of the initial volume control knob125.

After 925, the process transitions to 930. At 930, the processdetermines whether the volume level Current_Vol is within a secondthreshold of the volume level of any other volume marker of the volumebar. The second threshold is typically smaller than the first threshold.When the volume level Current_Vol is not within the second threshold ofany other volume level, the process transitions to 940.

Otherwise, if the process identifies (at 930) a volume level that iswithin a threshold of Current_Vol, the process sets (at 935) the volumelevel Current_Vol to the identified volume level. For instance, in theexample illustrated in FIG. 10, the process will define the volume levelCurrent_Vol to be the volume level 1015, when the control knob 1010 getswithin a second threshold of the volume level 1015. In some embodiments,the process also causes (at 935) the cursor to snap to the volume levelidentified at 930. Some embodiments snap to, and/or specify dashed linesfor, only volume levels of volume markers that are before the currentvolume marker.

After 935, the process transitions to 940. At 940, the process recordsthe volume level Current_Vol as the volume-level attribute of the volumemarker. At 945, the process then identifies the current x-coordinate ofthe cursor, maps this x-coordinate to a time value along the timeline115, and then records this time value as the time-value attribute of thevolume marker. As mentioned before, this time value is the time value ofthe volume-control knob of the volume marker.

After 945, the process determines (950) whether the click-and-dragoperation is still continuing. If so, the process returns to 915 torepeat its operations and update the volume marker attributes. Each timethe process reaches 950, it has updated the volume marker's volume andtime attributes. Hence, each time the process reaches 950, the graphicssystem can redraw the volume marker, the volume bar, and/or the otherattributes of this bar to provide an up to date representation of thevolume marker and volume bar on the display. The process terminates whenit determines (at 950) that the click-and-drag operation has terminated.

FIG. 11 illustrates a process 1100 for modifying a volume marker byperforming a click-and-drag operation on the marker's volume-controlknob (such as knob 225 for the volume marker 235 in FIG. 2). In someembodiments, this process 1100 starts when the user clicks within acertain distance of the volume-control knob and drags this knob by aslight amount. In other words, this click-and-drag operation starts (at1105) the process 1100. Once this process starts, its operation issimilar to the operations after 910 of the process 900 of FIG. 9A. Inother words, the operations 915-950 of the process 1100 are similar tothe similarly numbered operations 915-950 of the process 900. Thesesimilar operations are not further described below in order not toobscure the description of the invention with unnecessary detail.

FIG. 12 illustrates a process 1200 for modifying a volume marker byperforming a click-and-drag operation on the marker's duration-controlknob (such as knob 220 for the volume marker 235 in FIG. 2). In someembodiments, this process 1200 starts (at 1205) when the user (1) clickswithin a certain distance of the duration-control knob of a volumemarker, and (2) drags this knob by a slight amount. Once the processdetects this click-and-drag operation, the process identifies (at 1210)the current x-coordinate cursor. It maps (at 1210) this coordinate to atime value along the time axis 115.

Next, at 1215, it computes a new duration for the volume marker's ramp.This new duration equals the difference between the time value attributeof the volume marker (where this attribute corresponds to the time valueof the marker's volume-control knob) and the time value identified at1210. This difference can never be less than zero, as theduration-control knob can never pass the volume-control knob on thetimeline. At 1215, the process records the new computed duration in thevolume marker.

After 1215, the process determines (at 1220) whether the click-and-dragoperation is still continuing. If so, the process returns to 1210 torepeat its operations and again update the volume marker durationattribute. Each time the process reaches 1220, it has updated the volumemarker's duration attribute. Hence, each time the process reaches 1220,the graphics system can redraw the volume marker, the volume bar, and/orthe other attributes of this bar to provide an up to date representationof the volume marker and the volume bar on the display. The processterminates when it determines (at 1220) that the click-and-dragoperation has terminated.

As mentioned above, the duration of a particular volume marker can alsobe modified if another volume marker's volume-control knob pushes theparticular volume marker's duration-control knob towards the particularvolume marker's volume-control knob. In this circumstance, someembodiments use a process similar to process 1200, except that theprocess in this case deletes the volume marker when its ramp durationhas reached zero, as at this point the two volume-control knobs of thetwo volume markers overlap.

FIGS. 13 and 14 illustrate how some embodiments use the volume markersspecified along a volume bar to define the volume level of an audiotrack. FIG. 13 illustrates a mixer that receives audio tracks 1 to N andproduces an output audio based on these tracks. The mixer also receivesvolume levels for each track from a volume setting process 1300 for thetrack.

FIG. 14 illustrates one example of a volume setting process 1300. Someembodiments perform this process each time a user directs theseembodiments to play an audio track that has set according to theinvention. The user might direct the audio track to start playing fromits beginning or from some other part of the track. As mentioned aboveby reference to FIG. 1, a user in some embodiments can drag a timermarker 120 along a timeline 115 to specify where to start playing theaudio track.

The process 1300 initially identifies (at 1405) the volume marker thatsets the volume level for the part of the audio track that starts thecurrent play. When the audio track starts from its beginning, thisvolume marker is the initial volume marker associated with the initialvolume-control knob 125. However, when the audio track starts at sometime t within the track, the volume marker identified at 1405 is thevolume marker that has a time-value attribute that (1) is before thestart time t and (2) is the closest to the start time t. For instance,FIG. 15 illustrates an example of an audio track that starts to play ata time t1. In this example, the process 1300 identifies (at 1405) thevolume marker that is associated with the volume modification 1505. Thisis because this volume modification occurs before the time t1 and is theclosest modification to this time. At 1405, the process defines themarker that it identified at 1405 as the Current_Marker.

Next, at 1410, the process supplies to the mixer 1310 the volume levelthat is specified by the volume marker identified at 1405. In theexample illustrated in FIG. 15, this volume level is the level 1510. Theprocess then determines (at 1415) whether there is another volume markerafter the Current_Marker on the volume bar. If not, the processterminates. Otherwise, at 1420, the process identifies the volume markerthat is after the Current_Marker on the volume bar, and specifies thisidentified marker as the new Current_Marker. In FIG. 15, the next volumemarker is the marker for the modification 1515.

After 1420, the process transitions to 1425, where it stays until themixer has played the audio track up to the time value specified in theCurrent_Marker. The time value specified in this marker corresponds tothe time that the ramp associated with this marker ends. When theprocess 1300 is at 1425 and the track's play time falls between thestart and end times of the ramp associated with the Current_Marker, theprocess periodically (at 1425) (1) computes the volume level based onthe ramp's attributes, and (2) supplies the computed volume levels tothe mixer. As mentioned above, some embodiments specify the ramp as asmooth spline curve. Hence, the values computed at 1425 are value alongthis curve at different points in time.

FIG. 15 provides an example of the periodic computation at 1425.Specifically, this figure illustrates that while the track's play timefalls between the start and end times t2 and t3 of the ramp 1520, theprocess 1300 computes four volume levels, where each volume level isgenerated at a different time during the audio's play. The processcomputes the first level 1525 at time t4, the second level 1530 at timet5, the third level 1535 at time t6, and the fourth level 1540 at timet3.

Once the process 1300 determines (at 1420) that the play time has passedthe time value specified in the Current_Marker, it transitions back to1415. For instance, in FIG. 15, the process transitions back to 1415after it computes the fourth level 1540 and then determines that theplay time has past t3. The operation of the process 1300 from 1415 wasdescribed above.

The above-described embodiments have numerous advantages. Theseembodiments allow a user to set easily different volume levels atdifferent times for the same track. They enable the user to do this in avisual and intuitive manner. This volume control is especiallybeneficially when mixing several audio tracks, where at different timesthe volumes of different tracks need to be raised while others need tobe lowered.

For instance, this is a useful feature when dubbing commentary over theaudio track of a video clip. It is also useful when wishing to reducethe background music associated with a video clip in order to listen tothe audio component of the video clip. FIG. 16 illustrates one suchexample. This figure illustrates the GUI interface of a movie editingapplication. In this example, a user is utilizing the editingapplication to work on a video clip that has an audio track associatedwith it. The volume level of the audio track appears as a line bar 1605that is superimposed on the rectangular box 1610, which represents thevideo clip. This line bar is superimposed on this box since the user haschecked an edit volume button 1640.

In FIG. 16, the user has added a second audio track to the clip. Thisadded audio track appears as a rectangular box 1615 below the box 1610.A line bar 1620 is superimposed on the box 1615. This line barrepresents the volume level of the second audio track. As shown in FIG.16, the volume level of the video clip's audio component is increased ina time interval 1625, while the volume level of the added audio track isdecreased in this interval. This allows the viewer to hear the videoclip's audio much more clearly during the timer interval 1625. Anothervolume feature in FIG. 16 should be noted. This feature is the volumecontrol bar 1630. After selecting an audio track (which can be eitherthe audio component of a visual clip or a separate audio track), theuser can drag a marker 1635 along this bar to reduce or increase theoverall volume level.

FIG. 17 presents a computer system with which one embodiment of theinvention is implemented. Computer system 1700 includes a bus 1705, aprocessor 1710, a system memory 1715, a read-only memory 1720, apermanent storage device 1725, input devices 1730, and output devices1735.

The bus 1705 collectively represents all system, peripheral, and chipsetbuses that communicatively connect the numerous internal devices of thecomputer system 1700. For instance, the bus 1705 communicativelyconnects the processor 1710 with the read-only memory 1720, the systemmemory 1715, and the permanent storage device 1725.

From these various memory units, the processor 1710 retrievesinstructions to execute and data to process in order to execute theprocesses of the invention. The read-only-memory (ROM) 1720 storesstatic data and instructions that are needed by the processor 1710 andother modules of the computer system.

The permanent storage device 1725, on the other hand, is read-and-writememory device. This device is a non-volatile memory unit that storesinstruction and data even when the computer system 1700 is off. Someembodiments of the invention use a mass-storage device (such as amagnetic or optical disk and its corresponding disk drive) as thepermanent storage device 1725.

Other embodiments use a removable storage device (such as a floppy diskor Zip® disk, and its corresponding disk drive) as the permanent storagedevice. Like the permanent storage device 1725, the system memory 1715is a read-and-write memory device. However, unlike storage device 1725,the system memory is a volatile read-and-write memory, such as a randomaccess memory. The system memory stores some of the instructions anddata that the processor needs at runtime. In some embodiments, theinvention's processes are stored in the system memory 1715, thepermanent storage device 1725, and/or the read-only memory 1720.

The bus 1705 also connects to the input and output devices 1730 and1735. The input devices enable the user to communicate information andselect commands to the computer system. The input devices 1730 includealphanumeric keyboards and cursor-controllers. The output devices 1735display images generated by the computer system. For instance, thesedevices display IC design layouts. The output devices include printersand display devices, such as cathode ray tubes (CRT) or liquid crystaldisplays (LCD).

Finally, as shown in FIG. 17, bus 1705 also couples computer 1700 to anetwork 1765 through a network adapter (not shown). In this manner, thecomputer can be a part of a network of computers (such as a local areanetwork (“LAN”), a wide area network (“WAN”), or an Intranet) or anetwork of networks (such as the Internet). Any or all of the componentsof computer system 1700 may be used in conjunction with the invention.However, one of ordinary skill in the art would appreciate that anyother system configuration may also be used in conjunction with thepresent invention.

While the invention has been described with reference to numerousspecific details, one of ordinary skill in the art will recognize thatthe invention can be embodied in other specific forms without departingfrom the spirit of the invention. Thus, one of ordinary skill in the artwould understand that the invention is not to be limited by theforegoing illustrative details, but rather is to be defined by theappended claims.

1. A method for controlling a volume of an audio track, the methodcomprising: representing the volume of the audio track with a deformablegraph, wherein the graph is defined along two axes, wherein one axisrepresents time and the other axis represents volume level; receiving amodification to the graph, wherein the modification comprises a selectand drag operation, and produces three different portions of the graph;illustrating the modification on the graph as two points on the graph;and based on the illustrated modification, specifying volume levels ofthe audio track at different instances in time.
 2. The method of claim1, wherein the graph is a deformable line.
 3. The method of claim 1,wherein the portion of the graph between the two points is nonlinear. 4.The method of claim 3, wherein the portion of the graph between the twopoints is a spline curve.
 5. The method of claim 1, wherein the twopoints are separated along the time axis by a predetermined amount.
 6. Amethod for controlling a volume of an audio track, the methodcomprising: representing the volume of the audio track with a deformablegraph, wherein the graph is defined along two axes, wherein one axisrepresents time and the other axis represents volume level; receiving amodification to the graph; and based on the modification, specifyingthree different portions of the graph corresponding to at least threedifferent volume levels of the audio track.
 7. The method of claim 6,wherein the graph is a deformable line.
 8. The method of claim 6,wherein at least one of the three portions of the graph is nonlinear. 9.The method of claim 8, wherein the nonlinear portion is a spline curve.10. The method of claim 6, wherein at least one of the three portions ofthe graph remains unchanged.
 11. A method for controlling a volume of anaudio track, the method comprising: defining a graphical user interface(GUI); and defining a graph to represent the volume of the audio trackas a user interface item in the GUI, the graph for receivingmodifications to the volume of the audio track and for representing eachmodification in terms of a first control for controlling an amount bywhich the modification changes the volume and a second control forcontrolling a duration of the modification.
 12. The method of claim 11,wherein the first control is also for controlling a time location of themodification.
 13. The method of claim 11, wherein the first control is avolume-control knob.
 14. The method of claim 11, wherein the secondcontrol is a duration-control knob.
 15. A non-transitory computerreadable medium storing a computer program that when executed by atleast one processor controls a volume of an audio track, the computerprogram comprising sets of instructions for: representing the volume ofthe audio track with a deformable graph, wherein the graph is definedalong two axes, wherein one axis represents time and the other axisrepresents volume level; receiving a select and drag operation to thegraph; and specifying, based on the select and drag operation, threedifferent portions of the graph corresponding to at least threedifferent volume levels of the audio track.
 16. The non-transitorycomputer readable medium of claim 15, wherein the graph is a deformableline.
 17. The non-transitory computer readable medium of claim 15,wherein at least one of the three portions of the graph is nonlinear.18. The non-transitory computer readable medium of claim 17, wherein thenonlinear portion is a spline curve.
 19. The non-transitory computerreadable medium of claim 15, wherein at least one of the three portionsof the graph remains unchanged.
 20. A non-transitory computer readablemedium storing a computer program for execution by at least oneprocessor, the computer program comprising a graphical user interface(GUI), the GUI comprising: a display area to display an audio track; anda graph to representing a volume of the audio track, the graph forreceiving modifications to the volume of the audio track and forrepresenting each modification in terms of a first control forcontrolling an amount by which the modification changes the volume and asecond control for controlling a duration of the modification.
 21. Thenon-transitory computer readable medium of claim 20, wherein the firstcontrol is also for controlling a time location of the modification. 22.The non-transitory computer readable medium of claim 20, wherein thefirst control is a volume-control knob.
 23. The non-transitory computerreadable medium of claim 20, wherein the second control is aduration-control knob.
 24. A non-transitory computer readable mediumstoring a computer program that when executed by at least one processorcontrols a volume of an audio track, the computer program comprisingsets of instructions for: representing the volume of the audio trackwith a deformable graph, wherein the graph is defined along two axes,wherein one axis represents time and the other axis represents volumelevel; receiving a modification to the graph, wherein the modificationcomprises a select and drag operation, and produces three differentportions of the graph; illustrating the modification on the graph as twopoints on the graph; and specifying volume levels of the audio track atdifferent instances in time based on the illustrated modification. 25.The non-transitory computer readable medium of claim 24, wherein theportion of the graph between the two points is nonlinear.
 26. Thenon-transitory computer readable medium of claim 25, wherein the portionof the graph between the two points is a spline curve.